1. Field of the Invention
The invention relates to a liquid crystal display (LCD) panel, and more particularly to a method for manufacturing a wide visual angle LCD panel by multi-domain vertical alignment (MVA).
2. Description of the Related Art
Liquid crystal display (LCD) panels have many advantages, such as small volume, light weight, low power consumption and so on. Thus, LCD panels are popularly applied in electronic products, such as portable computers and mobile phones, instead of conventional cathode ray tubes (CRTs). However, current LCD panels have undesired narrow visual angles. Many methods for improving visual angles of LCD panels have been provided. For example, for a multi-domain vertical alignment (MVA) method known in the art, a pixel electrode is divided into two sub-pixel electrodes. When an LCD panel displays low gray level images, two data signals with different voltage levels are respectively provided to the sub-pixel electrodes via data lines.
FIG. 1 is a schematic diagram of a conventional LCD panel and peripheral driving circuits. As shown in FIG. 1, the LCD panel 1 is formed by interlaced data lines d11, d12, d21, d22 . . . dm1, dm2 and gate lines g1, g2 . . . gm. Each interlaced set includes two data lines and one gate line and is used to control a display unit, for example, the data lines d11 and d12 and the data line g1 are used to control a display unit mainly formed by a pixel electrode 30. As shown in FIG. 1, the equivalent circuit of the display unit comprises a pixel electrode (such as 30, 40, 50), thin film transistors q111-q1m2, q211-q2m2 . . . qn11-qnm2 for controlling data input, and storage capacitors c111-c1m2, c211-c2m2 . . . cn11-cnm2. Gate electrodes and drain electrodes of the thin film transistors are coupled to the gate lines g1-gn and data lines d11-dm2 respectively. All thin film transistors in the same row (that is coupled to the same gate line) are turned on via scan signals on the gate lines g1-gn, thereby controlling whether data on the data line d11-dm2 is written to corresponding pixel electrode.
Moreover, FIG. 1 also shows peripheral driving circuits of the LCD panel 1. A gate driver 10 provides scan signals to the gate lines g1-gn according to a predetermined scan order. When one gate line carries a scan signal, the thin film transistors within in all display units in the same row or the gate line are turned on. When one gate line is selected, a data driver 20 provides data signals to the m display units in the selected gate line via the data lines d11-dm2 according to prepared but not yet displayed image data. Each time the gate driver 10 finishes scanning all n gate lines, the display of a single frame is complete. Therefore, the object of displaying images is achieved by repeatedly scanning scan lines and outputting video signals.
FIG. 2 shows circuit structure of the pixel electrode 40. As shown in FIG. 2, there is a pair of data lines respectively on two sides of the pixel electrode 40, such as data lines d21 and d22, and the pixel electrode 40 comprises a pair of sub-pixel electrodes 401 and 402. The sub-pixel electrode areas 401 and 402 respectively comprise switch devices q121 and q122 which are coupled to the gate line g1 and the corresponding data lines d21 and d22. In order to reduce coupling equivalent capacitance CP1 between the data line d21 and the sub-pixel electrode 401 and coupling equivalent capacitance CP2 between the data line d22 and the sub-pixel electrode 402, in conventional methods, the distance in a direction P1 (that is horizontal direction) between the data lines and the sub-pixel electrodes is increased. Generally, the distance in the direction P1 between the data line d21 and the sub-pixel electrode 401 and the distance in the direction P1 between the data line d22 and the sub-pixel electrode 402 have to be more than 7□m (micro-meter), for the effect of the coupling equivalent capacitance to be effectively degraded. However, this also decreases the aperture ratio. The aperture ratio is a ratio of penetrable light which is calculated by dividing light-penetrable effective area by total area of the display unit. Thus, the decreased aperture ratio causes whole images to become dark.
Additionally, crosstalk is another factor which affects image quality of liquid crystal displays. For crosstalk, coupling capacitance effect from data lines and pixel electrodes causes image distortion of liquid crystal displays. Thus, it is desired to provide a liquid crystal display with high aperture ratio, wide visual angles, and decreased crosstalk.